The specific aims of this research are to investigate, document and evaluate the In-vitro comparative activity of 4-quinolone antimicrobials (norfloxacin, ciprofloxacin, ofloxacin, temolfloxacin, perfloxacin, fleroxacin, amifloxacin, and lomefloxacin) and compare these against one first generation (cefalozin), one second generation (cefonicid or cefuroxime), and two third generation (ceftazidime or ceftizoxime or ceftriaxone or cefepime) cephalosporin antibiotics. These agents will be tested against clinical bacterial pathogens isolated from different body sites of patients at Carolinas Medical Center. The 4-quinolones are a class of new synthetic antimicrobial agents that possess excellent broad-spectrum antibacterial activity, have favorable pharmacokinetic properties, and oral bioavailability. They offer hope and alternative therapy for treating infections that presently require parenteral therapy. the cephalosporins are broad-spectrum antibiotics that are being extensively used to treat variety of infections caused by gram- negative and gram-positive bacteria. The proliferation of cephalosporin derivatives in the past ten years has provided a multiplicity of choice for clinicians seeking the appropriate drug for a particular infection. The pathogens will be tested for antimicrobial susceptibility using the method of Kirby-Bauer on Muller-Hinton plates. An individual pathogen will be classified as sensitive or resistant to a particular antimicrobial agent according to the width of toxic zone. The test results will be entered into computer files and the dBase IV query language will be used to generate monthly summary reports on the percent susceptibility (sensitive vs resistant) of each pathogen against each antimicrobial agent. The results provided to Carolinas Medical Center will assist clinicians in selecting the appropriate antimicrobial with which to treat a particular infection.